Underdog (Korean: 언더독; RR: Eondeodog) (alternatively labelled A Dog's Courage) is a 2018 South Korean animated film about the story of abandoned dogs. The film is directed by Lee Chun-baek and Oh Sung-yoon and stars Doh Kyung-soo, Park So-dam and Park Chul-min. It was released in theaters on January 16, 2019.^[2][3][4][5]

The film opened the 22nd Bucheon International Fantastic Film Festival in July 2018.^[6][7] Tickets for the film were sold out in 9 seconds, setting a record for the shortest time for an opening film at the BIFAN to be sold in such time.^[8] It was also chosen to be screened in North Korea as the first act of the South Korea-North Korea film exchange program.^[9][10]

Underdog was featured in the Taiwanese Kaohsiung Film Festival in the Kids Fantasy section on October 20–21, 2018.^[11]

In March, 2019, Underdog was featured in Tokyo Anime Award Festival, being the first Korean film to do so.^[12] In June 2019, Underdog was featured in Annecy International Animated Film Festival, being the only Korean animation film out of eight to do so.^[13]

A blue and white collie dog named Moongchi is driven by his owner to a forest somewhere in North Korea where he is released and abandoned.

Moongchi waits for his owner to return. While waiting, he is discovered by a pack of stray dogs consisting of two Chihuahuas mates wearing vests, a German Shepherd named Gaeko, and their leader, a small scruffy Shih Tzu named Jjangah. They inform Moongchi that his owner won't return which he finds hard to believe until the conversation is interrupted by a car parking nearby, leaving a scrawny crippled dog on the roadside and driving away. Moongchi is mortified and begins to believe that he too has been abandoned. The strays carry the new crippled dog with them into a human town; there Moongchi encounters the local dogcatcher but makes a narrow escape with the help of another town stray named Bongji, and they return to the Strays' home inside a dilapidated abandoned building. They discuss their living conditions with the dangers of the dog-hunter and Gaeko mentions a distant paradise they could travel to by scent, only to be shot down by Jjangah.

The following day the strays travel to a nearby restaurant where a friendly chef is known to feed the dogs. There Moongchi sees a human he mistakes for his owner and chases them into the restaurant only to be hastily driven from the building. That night as Moongchi lies awake the sickly dog begins moving; she asks Moongchi to bring her to her mom and then collapses. The following morning she is found to have passed away. The dogs bury her in the buildings dirt yard along with other past graves where they gather and mourn; Moongchi leaves to disown his tennis ball into a river.

Moongchi witnesses a pack of wild dogs hunting a boar and running off into the mountains. The pack consists of a black dog named Bami, a pair named Shirley and Edward, and their son Trevin. They return to their den site where they discuss the recent lack of prey due to humans and their fear of human settlements. That day the town strays find that the friendly chef was fired for attracting stray dogs and they are no longer welcome.

The next day Moongchi goes to visit the wild dogs where he meets Trevin and follows him to their den site. He hopes to make friends with them with a bone as a gift, only to be told that town strays don't belong with wild dogs and sent back to town. That night Bongji is captured by the dog catcher and the stray town dogs again debate their living conditions. Gaeko mentions the potential paradise he vaguely remembers and Moongchi mentions living in the mountains like the wild dogs, but Jjangah chastises Moongchi's criticism of their lifestyle. Moongchi runs off and hopes to impress the wild dogs by driving goats from a human farm into the mountains for them to kill and eat, only for Edward to chastise him for endangering them by angering the humans. As expected, the goat farmer calls animal control services for the wild dogs resulting in Jacob and Trevin being captured and put into a pound. Moongchi is injected with a GPS tracking chip with intent on later using him to locate the other stray dogs.

Moongchi recalls his childhood in a puppy mill where he was separated from his mother and siblings to be sold in a pet store, where he was adopted by a family who were unaware of how large he would grow. That night he, Trevin and all other captive dogs are freed from the pound by the wild dogs. As they flee they discuss their need for a new home and Moongchi recalls the paradise Gaeko mentions. The town dog's abandoned building is destroyed by human construction and they too need a new home. Together they and the wild dogs agree to follow Gaeko to the land he remembers.

The dogs cross a highway, but Shirley and Edward are killed by a car collision. The dogs find that the fields on the other side make safe living grounds and successfully hunt a deer together. Bami tells Moongchi about her childhood in a puppy mill where dogs are abused until disposed of and how her mother was taken when she became too ill; Bami was almost doomed to the same life but managed to escape, ending up with the wild dogs.

The strays' newfound peace is short-lived as the dog-hunters find them using Moongchi's tracking device, but the dogs narrowly escape in a wildfire. Along their journey they encounter a household of friendly humans who rescue injured animals and have several crippled dogs. Moongchi attempts to leave the others due to suspecting the tracking chip in his neck but Bami refuses to allow it. They encounter the lead dog-hunter whom they defeat in a fight and leave in the middle of the forest, the man ending up in a mine field with no way out. Jjangah decides that he will stay with the humans and they make their goodbyes before the strays continue their journey.

The strays arrive at the border of the Korean Demilitarized Zone and see the paradise they've been seeking on the other side of the barbed fence wall in South Korea. Gaeko recalls he was once a guard dog here. The stray dogs escape through the gate into the wilderness on the other side except for Moongchi, who gets stuck behind. After being chased around by the military personnel, Moongchi leaps over the wall and escapes with the strays into the peaceful, uninhabited wilderness. The film's end credits show the strays living a happy life in their new home and Moongchi and Bami eventually having a litter of puppies, and it's revealed that Jjangah has started a family with his new mate as well.

• Doh Kyung-soo as Moongchi (a Border Collie)^[14]
• Park So-dam as Bami (a wild dog)^[15]
• Park Chul-min as Jjangah (a Shih Tzu)^[16]
• Lee Jun-hyuk as Hunter
• Jeon Sook-kyung as Ari
• Yeon Ji-won as Tari
• Kang Seok as Gaeko (a German Shepherd)
• Park Joong-geum as Cari
• Tak Won-jung as Bongji (A Scottish Terrier)

Director Oh Sung-yoon had previously directed the animated film Leafie, A Hen into the Wild (2011).^[14] The production of Underdog started in April 2013 and ended in June 2018.^[17] Dubbing began in January 2016.^[18]

Before its premiere, Underdog was sold to 69 territories including France, United States, Canada, Hong Kong, Malaysia, Singapore and Indonesia.^[19]

• South Korean animation
• List of Korean animated films